This guide provides official download links for the Cubot J3 stock firmware. The J3 was a budget Android Go smartphone released in 2018 with MediaTek MT6580 processor and Android 8.1 Go Edition. If your device has problems like bootloop, camera issues, battery drain, or charging problems, flashing the stock firmware can fix these issues.
User Data Advisory for the Cubot J3
Critical Pre-Flash Warning: This will erase all data on your Cubot J3. Back up your photos, apps, and files first. Incorrect flashing can damage your IMEI number.
Cubot J3: Device Specifications
Make sure these specs match your phone before flashing:
- Device Name:
- Cubot J3
- Release Date:
- 2018
- Chipset:
- MediaTek MT6580 Quad-Core 1.3GHz
- Display:
- 5.0 inches, 480 x 960 pixels, 18:9 ratio
- Battery:
- 2000 mAh removable
- RAM/Storage:
- 1GB RAM / 16GB Storage
- Key Features:
- 8MP rear camera, 5MP front camera, Face unlock, Android 8.1 Go
Required Downloads
You need these tools to flash your phone:
- SP Flash Tool (Latest Version)
- MediaTek USB Drivers
- Cubot J3 firmware file (choose version below)
Cubot J3 Firmware Download Links
| Version (Build Date) | Android Version | Size | Download Link |
|---|---|---|---|
| J3_V23 (Jun 2020) | 8.1 Go | 653MB | Download (MEGA) |
| J3_V18 (May 2019) | 8.1 Go | 652MB | Download (MEGA) |
| J3_V15 (Jan 2019) | 8.1 Go | 655MB | Download (MEGA) |
| J3_20180525 (May 2018) | 8.1 Go | 640MB | Download (MediaFire) |
How to Flash Cubot J3 Firmware
Follow these steps to flash your phone:
- Preparation: Download firmware, SP Flash Tool, and drivers. Extract all files to one folder.
- Install Drivers: Run the MediaTek driver installer.
- Load Firmware: Open SP Flash Tool, click “Scatter-loading File,” select the scatter file from firmware folder.
- Set Mode: Choose “Download Only” to keep your IMEI safe.
- Flash Phone: Turn off phone, remove battery for 10 seconds, put back, hold Volume Up + Volume Down, connect USB cable, release buttons when flashing starts.
Common Problems and Solutions
Here are fixes for common Cubot J3 issues:
1. Phone Stuck in Bootloop
Problem: Phone keeps restarting at Cubot logo screen.
Solution: Remove battery, hold power button for 30 seconds to discharge. Put battery back and try turning on. If still bootlooping, flash latest firmware V23 using SP Flash Tool.
2. Camera Not Working or Black Screen
Problem: Camera app crashes or shows black screen.
Solution: Clear camera app data: Settings > Apps > Camera > Storage > Clear Data. Restart phone. Check camera permissions in Settings > Apps > Camera > Permissions.
3. Battery Drains Very Fast
Problem: 2000mAh battery doesn’t last long despite Android Go.
Solution: Android 8.1 Go should help with battery life. Close unused apps, disable location services, reduce screen brightness. The 1GB RAM means phone works harder.
4. Phone Won’t Charge or Slow Charging
Problem: Phone doesn’t charge or takes very long to charge.
Solution: Clean charging port with toothpick. Try different cable/charger. Remove and reinsert battery. Check if charging port is loose or damaged.
5. Phone Runs Very Slowly
Problem: Phone is very laggy with only 1GB RAM.
Solution: Android Go is designed for 1GB RAM but still limited. Keep only essential apps installed. Clear cache regularly. Restart phone every few days. The MT6580 processor is quite weak.
Frequently Asked Questions
- Why does my phone keep bootlooping after trying to install custom ROM?
- The Cubot J3 doesn’t handle custom ROMs well due to the MT6580 processor and Android Go setup. Always flash back to stock firmware if you have issues.
- Can I upgrade from Android 8.1 Go to regular Android?
- No, the 1GB RAM and MT6580 processor can only run Android Go efficiently. Regular Android would be too slow.
- Why is the camera quality so poor despite being 8MP?
- Budget phones often use software to make cameras seem higher quality than they are. The MT6580 processor also limits camera processing power.
- My phone shows “Not Verify” after flashing – is this normal?
- Yes, this is normal after flashing firmware and won’t affect phone operation. You can safely ignore this message.
- Can I root my Cubot J3?
- Rooting is possible but risky on Android Go devices. It can cause bootloops and other issues. Not recommended for daily use.
Conclusion
Flashing the official V23 firmware fixes most Cubot J3 problems including bootloop, camera issues, battery drain, and charging problems. The Android 8.1 Go Edition is specifically designed for the 1GB RAM and MT6580 processor limitations.
If this guide helped you fix your J3, share your experience in the comments to help other users!
